Media data including a movie and sounds are generally supplied in an encoded manner in which data size is compressed. For example, movie data is supplied after having been encoded into MPEG (Moving Picture Experts Group) or other format. On the other hand, these pieces of data are often supplied after having been encrypted by the DRM (Digital Rights Management) or other technology for protection of copyright. Such encrypted media data will be hereinafter referred to as protected data. When an information processor plays such protected data, it is necessary to decode protected data first so as to generate raw data. Here, the term “decoding” refers to decrypting encrypted protected data and decoding encoded data into original raw data. Raw data represents the movie or audio content in an as-is manner. In the case of a movie, raw data includes a plurality of continuous frame images in bitmap format. In the case of sounds, on the other hand, sampling data (e.g., PCM) obtained by sampling (quantizing) an analog audio signal corresponds to raw data.